Display device with metal layer between pixel defining layer and opposite electrode

1. A display device comprising:

sub-pixels disposed on a substrate, the sub-pixels each including:

a pixel electrode;

an opposite electrode facing the pixel electrode;

an emission layer disposed between the pixel electrode and the opposite electrode; and

a pixel-defining layer made of an organic material and completely surrounding the emission layer such that the pixel defining layer separates each sub-pixel from other sub-pixels; and

a metal layer disposed between the pixel-defining layer and the opposite electrode, the metal layer contacting the opposite electrode.

2. The display device of claim 1 , further comprising an inorganic protective layer disposed between the metal layer and the pixel-defining layer.

3. The display device of claim 2 , wherein the inorganic protective layer includes material comprising at least one of indium zinc oxide (IZO), indium tin oxide (ITO), silicon oxide (SiO 2 ), silicon oxynitride (SiON), and silicon nitride (SiN x ).

4. The display device of claim 1 , wherein the metal layer includes at least one layer of titanium (Ti) and at least one layer of aluminum (Al).

5. The display device of claim 4 , wherein the at least one layer of titanium (Ti) and the at least one layer of aluminum (Al) are stacked relative to each other.

6. The display device of claim 1 , wherein the metal layer includes:

pad portions contacting the opposite electrode above the pixel-defining layer; and

connectors electrically connecting the pad portions to each other.

7. The display device of claim 6 , wherein

the connectors are disposed in a mesh shape crossing in a horizontal direction and a vertical direction, and

the pad portions are disposed at intersections of the mesh shape.

8. The display device of claim 7 , wherein the pad portions are disposed at every intersection.

9. The display device of claim 7 , wherein the pad portions are disposed at less than all of the intersections.

10. The display device of claim 6 , wherein all of the pad portions contact the opposite electrode.

11. A display device comprising:

a sub-pixels disposed on a substrate, the sub-pixels each including:

a pixel electrode;

an opposite electrode lacing the pixel electrode:

an emission layer disposed between the pixel electrode and the opposite electrode; and

a pixel-defining layer surrounding the emission layer; and

a metal layer disposing between the pixel-defining layer and the opposite electrode, and metal layer contacting the opposite electrode, wherein

the metal layer includes;

pad portions contacting the opposite electrode above the pixel-defining layer, less than all of the pad portions contacting the opposite electrode; and

connectors electrically connecting the pad portions to each other.

12. The display device of claim 6 , further comprising spacers disposed on the pixel-defining layer between multiple pixels, the spacers protruding toward the opposite electrode.

13. The display device of claim 12 , wherein the spacers are disposed for all of the sub-pixels.

14. The display device of claim 12 , wherein the spacers are disposed for less than all of the sub-pixels.

15. The display device of claim 12 , wherein the pad portions are disposed on all of the spacers.

16. The display device of claim 12 , wherein the pad portions are disposed on less than all of the spacers.

17. The display device of claim 1 , further comprising:

a display area in which the sub-pixels are disposed; and

a cathode power supply unit disposed outside the display area, wherein the cathode power supply unit applies a same voltage to the opposite electrode of each sub-pixel and the metal layer.

18. The display device of claim 17 , wherein

the display area includes a first side, a second side, a third side, and a fourth side, wherein

the first side and the second side face each other,

the third side connects an end portion of the first side to an end portion of the second side, and

the fourth side connects another end portion of the first side to another end portion of the second side, and

the cathode power supply unit includes:

a power supply line surrounding the first side, the second side, and the third side, and surrounding a portion of the fourth side outside the display area;

a connection terminal of the metal layer electrically connected to the power supply line; and

a connection terminal of the opposite electrode electrically connected to the connection terminal of the metal layer.

19. The display device of claim 18 , further comprising:

an intermediate connection terminal disposed between the power supply line and the connection terminal of the metal layer, wherein

the intermediate connection terminal and the pixel electrode include a same material and are disposed on a same layer, and

respective layers from the power supply line to the connection terminal of the opposite electrode are disposed stepwise such that a step difference is provided between the respective layers.

20. The display device of claim 18 , wherein a portion in which the power supply line, the metal layer, and the opposite electrode are electrically connected includes a portion in which the power supply line surrounds the first, second, and third sides.

21. The display device of claim 20 , wherein the portion in which the power supply line, the metal layer, and the opposite electrode are electrically connected includes a portion in which the power supply line surrounds a portion of the fourth side.

22. The display device of claim 1 , wherein the metal layer includes:

first parallel connectors extending in a first direction;

second parallel connectors extending in a second direction intersecting the first direction; and

pad portions where first and second connectors intersect, wherein the first parallel connectors, the second parallel connectors, and the pad portions are disposed in a same layer.

23. The display device of claim 22 , wherein the pad portions have a width greater than either of the first parallel connectors or the second parallel connectors.